I´m an aspiring DP and shooting my first short film in Februar. We have a little money from the film fund here in Berlin, but it´s still a very low- or even no-budget production. first of all, a little information, before I start with the questions:

1. the film plays entirely in a hospital, 11 night scenes, 5 day scenes. we´re shooting in winter in Berlin, which means that we would use lamps to simulate the day light. (the story plays in the middle east... another small challenge.)
2. we´re shooting with the panasonic HVX200 and the P&S 35 Adaptor.
3. I want to simulate a bleach-bypass in the post production, so basically I want to create a black and white image on top of the color image, and mix them with layers-modes. (I still don´t have a colorist, maybe he´ll have better technics) I´m aiming for a gentle BB look, not really all the way like "Saving private Ryan", maybe something like "se7en", maybe a little gentler.
4. we´re aiming for a 35mm Blow-up at the end.

and now, for the questions:
1. with BB-process in film, you usually should under-expose by about 1 stop, to create a softer negative. I did a little tests with photoshop, and I´m having a problem with the shadows, more than with the highlights. does it mean that with HD I should over-expose? (it´s actually like a positive, so it makes sense)
2. also, the lighting, even with film, should be very soft. now, that scares me a little, because HD is anyway not very tolerant for many f-stops. If I´m going for BB, does it mean that I should light my sets really really soft and without contrast? I like to light a little harder, even with video... should I really avoid it? what I´m asking is, am I going for very soft and balanced shots, or am I allowed to "let it burn"?
3. If I know now that I´m going to make a bleach bypass, and I want to go for a look that´s a little dirty with high contrast and little saturation, can I save a little money and shoot with HDV? (We can have a sony Z1 for free, or a HVX200 from rental) the production design could use the extra money, but since we want a blow-up I thought I should stick with the pure HD, progressive scan.

I thank you a lot in advance for the response, if anyone has any experience with HD and BB I would be happy to hear stories, ideas and conclusions. It´s not only my first film, I also wrote the script and it´s very important to me that it works... like for all of us.

HD is not Film, then a lot of light set ups and film treatment are not the same..
In my experience, to get the image that you want in HD you must try to get the most of image information in shooting to be change in post production.
sometimes is not a good idea get the final image in the shooting because of the latitude of the image sensor in the digital cameras. Usually the digital cameras have a better response in low light conditions what means if you work in that light range have more control of the image.

Be carefull with high contrast ratios, specially in the flesh tones.. an usual mistake is get a "yelowish" flesh tone when you overexpose showing the "digital" root of your image..

Please test your camera and light situations and post productions process before shooting to be sure which setup is the best for your project.

about the tests: of course I would ask the rental house to have the camera and the p&s adaptor before the actual shooting, and I hope I´ll be also able to take them on location and not do the tests in the rental house, but I´m surely not going the have the lighting set up that I´ll have by the shoot... I´m planning to use a lot of practicals (I still need to discuss that with my "Oberbeleuchter" - the gaffer) but it still won´t be the same set up that we´ll have by the shoot. Does anybody know any good ways to test the camera, the adaptor, the exposure level and the post-production process without having the entire light set up there? we have a lot of sets that would be lighted with three 6k for example, and they offer very different light from the night scenes, and they are probably the most complicated to expose and color-correct. I won´t have those 6k´s for the tests, just german winter...

IF you do actually output or go back to film you can BB the internegative or realese print. However this would require even more testing and more dollar bills, but it could give you a really cool unique outcome. If you have the budget try it. Test It.

I think the best way is to shoot as clean as possible, get you're exposures perfect, Video doesn't recover from overexposure. And puling up the black levels reveals noise and a greyer rendition.

Then increase the contrast to your preference, and desaturate it accordingly. This should give you more freedom during color correction.

If you want those deep crushed blacks be careful and make sure your actors have enough fill. I've needed the background to fall of into complete shadow and I knew i would do it in the timing, but when I crushed the blacks in post my actors face became a little too dark on the shadow side.

A good on the fly way to check that is to drop you're pedastal setting down. It crushes the blakcs and it will give you an idea of how much fill you might need to add.

Im actually doing the same thing right now on the short im DPing. Using the Z1 and p+s techning Mini35 , I try to achieve the best material to work with later on post.

Like most people here say, I recommend you not to over expose when shooting video. Actaully i think its best to expose for the highlights, than make sure you have enough detail in the shadows to work with. you must figure out the best way to achieve this with lighting setups, according to what you are shooting.

Im shooting lots of day-exterior and exposing for highlights. in a bright sunny day I get under-exposed shadows, so I use 8*8 silvers to bounce the daylight back .